Abstract:

 Aiming at the problem of the large perturbation in the initial position and azimuth angle for a spacecraft reaching the terminal area energy management (TAEM) interface, a new TAEM orbit algorithm based on iterative correction is designed. First of all, the ground track is used in the algorithm to piece the lateral guidance law and track the dynamic pressure-altitude profile which is generated based on the altitude and velocity constraints of the initial and ending point of TEAM to design the longitudinal guidance law. Secondly, the iterative correction is used in the algorithm to determine the position of the heading alignment cylinder (HAC). At last, the trajectory can be adjusted rapidly its final radius until the required conditions for approach and landing interface are met. The simulation results demonstrate that the TAEM orbit algorithm based on iterative correction calculates the referenced trajectory rapidly by the spacecraft’s states and the request of landing is satisfied by the control function.

Key words: Lateral guidance law, Longitudinal guidance law, Iterative correction, Ground track, Heading alignment, Energy management